Gerard C Adams, Jr., Associate Professor 

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          Ash Decline in Michigan Forests: In 2006-2009 a major research focus will be the "Assessment of Decline and Contributing Diseases in White Ash Stands in Michigan" funded by the USDA Forest Service. This research will include an emphasis in PCR and fluorescent monoclonal-antibody detection of Ash Yellows phytoplasma and Aster Yellows phytoplasma in white ash. The project will provide a current and detailed estimation of the role of various diseases in white ash decline in Michigan forests. It will examine the relationship between presence of ash yellows phytoplasma and poor crown conditions, and presence of ash yellows phytoplasma and other visual symptoms of decline. The study will examine and identify the presence of root and butt rots, including specific Armillaria species, and estimate their role in white ash mortality. The study will measure the amount of ash yellows in Michigan forests with white ash, and determine the impact of Armillaria root rot and other butt rots on ash decline.

         Massive Death of Alnus incana subsp. tenufolia in North America:A continuing research effort funded by the USDA Forest Service involves study of the cause of "Alder Dieback and Mortality in the Southern Rocky Mountains and Alaska" in cooperation with Dr. James Worrall and Lori Trummer, USFS. Our component of the study involves research on the identification of the causal agents and a comparison of their virulence and population diversity in relation to strains from other regions. One purpose of the study is to determine whether the massive die-off is caused by a new introduced [exotic] pathogen.

          Shoot Blight and Crown Rot of Pines: We continue studies of the latent pine pathogens Diplodia pinea and D. scrobiculata (=Sphaeropsis sapinea Type A & B). Our current research involves proving that forest stands free of these endophytic fungi and latent pathogens exist in Michigan, and that pine seedlings can be grown in nursery beds free of these fungi. The pathogens cause the most common and economically damaging diseases of most pine species. Approximately 30 million pine seedlings a year are grown in Michigan nurseries where only white pine is not affected by the pathogens. Losses of hundreds of hectares of pine seedlings and saplings due to Diplodia canker and death are being reported in Michigan, annually (Michigan DNR reports). The pathogens also readily contaminate nursery beds as saprophytes on plant debris. Disease symptoms develop following plant stresses, especially drought, hail, and frost injuries.

          Late Blight of Potato: Our newest research project is a study of the genetics of Phytophthora infestans the causal organism of ate Blight of Potato. The researchwill focus on characterizing the mechanisms of asexual variation that give rise to new races, new virulence spectra and increased resistance to fungicides in plant pathogen populations in the absence of sexual recombination. Less common mechanisms resulting in rare sexual recombination will also be studied. The research will secondarily focus on characterizing pathogen population shifts in the field and detecting pathogens prior to their emergence. The research should directly benefit the farmers in Michigan that grow potato and tomato crops by improving the deployment of available genetic resistance in the crops and more effectively decreasing disease losses. Research results will be applied to improving disease management strategies including decreasing ineffective use of fungicides on food crops. Aspects of the research should ultimately benefit society by improving strategies to combat pathogens. Research will concentrate on P. infestans the causal agent of potato and tomato late blight, diseases that are increasingly damaging Michigan food crops. We will investigate the hypothesis that rearrangements, accumulation of aberrations, and loss, of chromosomes are mechanisms responsible for generating asexual variation in field isolates. Additionally, we will investigate the hypothesis that rare events of the sexual mechanisms of polyploidy and interspecific hybridization may be responsible for generating variation in field isolates.

          Fungal Systematics and Phylogenetics; The Ascomycetes: Fungal molecular phylogenetics is a major focus of our research. My personal research is on fungi in the Ascomycetes in the family Valsaceae, including Valsa, Leucostoma, Valseutypella, and Valsella, and their asexual forms in Cytospora. These fungimcause cankers on most tree species, both gymnosperms and angiosperms. The species in the genus are not readily identifiable based on morphology in nature or in the laboratory. I have been sequencing the ITS rDNA, the 3'-end of the LSU rDNA, the Elongation Factor-1α, the Histone H, and the β-tubulin genes of field collections of the Valsaceae from conifer and deciduous trees. These have been compared to sequences of cultures from the Type culture collectionsof all species of Valsaceae that could be obtained. Members of the Diaporthales, other than the Valsaceae, and some Diatrypales have been sequenced because a number of described Cytospora species were discovered to be members of these related groups. A phylogeny of the Valsaceae has been used to examine the evolution of morphological characters and of plant host specificity. Results of the phylogenetic analysis show frequent and rapid evolution of host range. The morphological characters which are the basis of the current taxonomic system for distinguishing genera and species are not being maintained along an evolutionary lineage, therefore a speculation is that the morphology is altered by the physical and chemical properties of the bark of the host.

          Fungal Systematics and Phylogenetics; The Basidiomycetes: Fungal molecular phylogenetic studies of the genus Athelia [Basidiomycotina, Corticiaceae] have been another focus of my research. I have been sequencing the ITS rDNA and the mitochondrial small rDNA of members of this genus and sister taxa. Results from this incomplete project have been included in two collaborative projects. One project in collaboration with Brad Kropp [Utah State] involved the discovery of the sexual state of a species of Rhizoctonia and description of a new genus and species for Rhizoctonia species having clamp connections. A second project has been completed on the identification of cold-temperature Basidiomycetes that are storage pathogens, in collaboration with Claudia Jasalavich. Recently our lab has studied phylogenetic relationships among the toxic white species of the poisonous mushrooms in Amanita. This research is being continued by Dr. Heather Hallen. Other mushrooms are also studied in our research program, such as the genera Conocybe, Gastrocybe, and others. These studies often include poisonous species and assays of the toxins they produce.

 Recent graduate and undergraduate students from our lab include:

Dr. Heather E. Hallen who worked on the poisonous mushrooms Amanita, with a study of Amatoxins and Phallotoxins in Indigenous and Introduced South African Amanita, a phylogeny of Amanita section Phalloideae, a study of the identity of Amanita species infected with Hypomyces hyalinus, and a toxicity and phylogenetic study of Conocybe lactea and related genera and species especially gastroid forms in the Bolbitiaceae.

Dr. Mursel Catal who worked on designing and testing molecular probes for species-specific detection and quantification of latent pathogenic fungi of conifer foliage. This research included successful development of molecular diagnostic tools for over 15 important pathogens.

Zachary Blankenheim, M.S. who worked on the source and spread of Dogwood Anthracnose in Michigan and the molecular detection and diagnosis of the pathogen Discula destructiva. This pathogen is being imported into Michigan on symptomless nursery stock of Cornus spp. and multiplying in the nurseries, then infecting and killing native stands of C. florida on outplanting as landscape trees.

Brandi Hughey, formerly an undergraduate in our laboratory, has completed a study of the phylogeny of the anomalous stalked puffball Calostoma a Gasteromycete [Basidiomycotina] based on sequence of both nuclear small and large rDNA and mitochondrial small and large rDNA molecules. In collaboration with Tom Bruns [UC Berkeley], David Hibbett [Harvard] and Rytas Vilgalys [Duke] she has written a manuscript for Mycologia describing the relationship of Calostoma to the Boletales and related Gasteromycetes. Further study of Calostoma is continuing in Dr. Hibbett's lab at Clark University.

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